1. Field of the Invention
This invention relates to exercise devices for humans and, more particularly to a swim training devices, wherein the user wears the footwear of this invention to increase and maintain their cardiovascular condition and to train competitively for swimming events. The swimming fin of the instant invention provides a swim training fin similar in theory to the earlier and highly successful swim training fins of the '385 patent and the '328 patent, referenced above. However, this device uses a novel and aesthetically pleasing hydrodynamic streamlined design for increasing human efficiency and providing superior training and cardiovascular results.
2. Previous Art
As noted above, this inventor's, Dr. Hull's, prior devices have been highly successful in aiding and facilitating swimming and cardiovascular training. Dr. Hull's above two fins represent major breakthrough in swim training and, in fact created a whole new category of fin, called a swim “training fin”. Not only was the fin successful from a training point of view, but also it has been a commercial success.
The fins of the above referenced patents made possible the practicing of swimming at race pace without having to endure the potential injury producing stresses experienced at race pace. This is especially important in preserving the shoulder joints and muscle of swimmers while enabling them to establish the necessary coordination and superior levels of cardiovascular conditioning. The fins of the above referenced patents are instrumental in assisting and facilitating many swimmers, including world class and Olympians, to achieve their personal best, including world records.
Through observation, it has been found that ankle range of motion is a primary determiner of the proficiency of a swimmer. The average person does not swim proficiently because of this lack of ankle range of motion. The average person is substantially less proficient at swimming as compared with walking or running. Ordinarily, a person's legs develop primarily for use on land, i.e. walking or running. Most people are not able to effectively transfer to the water the abundant leg power they enjoy on land. The ability to transfer leg power to the water is dependent on the ability of the foot to deflect or displace water off the end of the foot in a rearward direction. This ability is dependent on the forward range of motion of the foot at the ankle (plantar flexion).
If all other attributes are equal (i.e. foot size, foot shape, leg length and strength), an ankle range of motion of less than 60° results in an average level of swimming proficiency. The farther this range is below 60°, the less proficient the individual will be.
Almost without fail, an individual who posses ankle range of motion of at least 60° will be an above average swimmer. An ankle range of motion of 60° or more is not common. The dorsal surface of this swimmer's foot with this ankle range of motion will deflect water backward during a substantial portion of the kicking movement.
An elite swimmer will have an ankle range of motion past 60°. Typically, there are few who possess ankle range of motion as much as 70° to 75°. These individuals are able to achieve world record status. Previous swim training fins were found to work well for the uncommon person possessing an ankle range of motion of at least 60°.
A training fin is a fin which includes a boot portion and compared with other fins, a shorter blade. The training fin is characterized by its ability to enable a user to practice swimming at steady fast pace, such as a race pace without having to endure the potential injury producing stresses experienced at race pace. Also, a fin to be categorized as a swim training fin must allow the user to get an advantage by its use. For example, if a fin, even though having a short blade does not provide the user with an advantage for its use then it is not a true swim training fin. A training fin must in more technical terms provide for a net gain between propulsion versus the drag created by the fin and its usage.
By definition a swim fin must have a certain amount of hydrodynamic structure to it. Early fin structures, such as the inventor's herein, provided a substantial number of swimmers with an advantage for its use. Thus, for these swimmers, the earlier fins provided a net increase in propulsion as a result of its use.
To derive optimum benefit from the earlier fins, the suggested range of ankle motion was 60° or more. Through observation it has been noted that the earlier fins were not as effective for swimmers having ankle range of motion of less than 60°. As a result of the success of the earlier fins, the desire to make the fins more usable for more users became stronger. The clear problem was that while the fin design worked extremely well for the category of swimmers having an ankle range of motion of at least 60°, a large portion of those desiring such a device could not use the earlier fins successfully or generate the desired efficiency. Thus, the inventor was faced with changing the design of a highly effective and popular fin to accommodate for persons with less range of ankle motion. However, it would be unacceptable to do this at the cost of the popularity for the training fin's initial audience. A complete redesign was necessary, while preserving the principles set forth above.